1. Field of the Invention
Aspects of the present invention relate to a crucible heating apparatus, and a deposition apparatus including the same, and more particularly, to a crucible heating apparatus including a band having contact parts, and a deposition apparatus including the same.
2. Description of the Related Art
Recently, research on implementing large displays, and improving the quality of the displays, has been widely performed, utilizing the advantages of thin and lightweight structures of Flat Panel Displays (FPDs), such as Liquid Crystal Displays (LCDs), and Organic Light Emitting Diodes (OLEDs). Among the FPDs, the OLED may be a next generation FPD capable of providing rapid response speed, enabling color representation without a color filter, and solving problems of conventional OLEDs, without using a separate light source.
Generally, an OLED has a predetermined pattern of pixel electrodes formed on a substrate. Organic layers, such as a hole transport layer, an organic emission layer, an electron transport layer, and so on, are sequentially formed on the pixel layer, and an opposite electrode is formed on the organic layers.
Organic layers of an OLED may be formed by photolithography. However, during photolithography, the organic layers can be exposed to moisture during a resist delamination process, and an etching process. The moisture can cause problems when depositing an organic layer.
In order to solve the above problems, a method of evaporating, sublimating, and vacuum depositing an organic material in a vacuum chamber may be performed, to form the organic layers. Such a vacuum deposition method includes positioning a substrate, on which an organic layer is to be formed, in the vacuum chamber. Then, a pattern mask, including a plurality of pattern parts, is disposed under the substrate. At this time, a crucible heating apparatus, containing an organic material for deposition on the substrate, is disposed under the pattern mask at a predetermined distance.
The crucible heating apparatus evaporates the organic material, which has the pattern of the pattern mask, using a heater, to form an organic layer on the substrate. Therefore, the crucible heating apparatus is an important apparatus that exerts a direct influence on characteristics of the organic layer.
A conventional crucible heating apparatus includes a crucible that includes a main body having an open upper part, to contain a material to be deposited, and a cover coupled to the upper part of the main body, having an opening for ejecting the material. A temperature control part is disposed at the exterior of the crucible heating apparatus, to control a temperature thereof. The temperature control part is electrically connected to the main body, by a thermocouple. Therefore, since a temperature of the deposition material contained in the main body can be obtained by the thermocouple, it is possible to control the deposition of the material, by adjusting a heater that heats the crucible.
In the conventional crucible heating apparatus, the thermocouple and the main body of the crucible are in point contact with each other. For this reason, when the thermocouple is attached or detached, to perform maintenance on the crucible, or to exchange the deposition material, it is difficult to contact the thermocouple with the main body, at the same position. Therefore, it is difficult to reproduce the same temperatures.
On the other hand, a non-contact thermocouple can be connected to a band spaced a certain distance from the exterior of the main body, without being directly connected to the main body. Therefore, temperatures of the heater and the deposition material may both be detected, such that a temperature higher than the actual temperature of the deposition material is detected, thereby causing problems in the accuracy of the temperature.